1. Field of the Invention
The present invention relates generally to a mask inspecting method, and more specifically, to a mask inspecting method that simulates optical behaviors such as a pattern image projected on a wafer from a mask using the same light with the same energy.
2. Description of the Prior Art
A conventional semiconductor process forms various semiconductor components by applying masks used for patterning wafers and semiconductor substrates. As the development of integrated circuit technologies progresses, products are becoming miniaturized, and thereby the density of circuit layouts and critical lines in semiconductor devices becomes more precise. Due to this trend, the defect tolerances of mask patterns in masks are reduced. An important issue in the field is therefore how to detect defects of mask patterns and eliminate those defects that would cause reduction in yields.
When defects are found they may be repaired, or masks may be abandoned for those defects that are impossible or not easy to be repaired. Additionally, some problems caused by defects may become worse as the defects are repaired; in other words, defect elimination requires a lot of time and money. To simplify the process, only those defects which could cause reverse effects when transferred to wafers during exposure should be eliminated. Images of a same mask pattern transferred to wafers with different processing parameters will be different, leading to different effects upon the wafers, so it is difficult to accurately simulate the transferring results of a mask in a specific parameter.